code: def __call__(self, x):
      mu = np.dot(x, self.theta)
      return np.random.normal(mu, 1)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import tensorflow
  from tf_agents.bandits.environments import stationary_stochastic_py_environment
  from tf_agents.policies import random_py_policy
  from tf_agents.specs import array_spec
  from tf_agents.trajectories import time_step
label_desc: Use image node_id 2 for calling the LinearNormalReward obj's underlying member method code with example usage: obj.__call__(x) and returns: np